Mylnikov V Yu, Dudelev V V, Rafailov E U, Sokolovskii G S
Ioffe Institute, 26 Polytechnicheskaya Str., St. Petersburg, 194021, Russia.
Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya St. 29, St. Petersburg, 195251, Russia.
Sci Rep. 2022 Oct 7;12(1):16863. doi: 10.1038/s41598-022-20621-w.
In this paper, we extend the paraxial conical refraction model to the case of the partially coherent light using the unified optical coherence theory. We demonstrate the decomposition of conical refraction correlation functions into well-known conical refraction coherent modes for a Gaussian Schell-model source. Assuming randomness of the electrical field phase of the input beam, we reformulated and significantly simplified the rigorous conical refraction theory. This approach allows us to consider the propagation of light through a conical refraction crystal in exactly the same way as in the classical case of coherent radiation. Having this in hand, we derive analytically the conical refraction intensity both in the focal plane and in the far field, which allows us to explain and rigorously justify earlier experimental findings and predict new phenomena. The last include the counterintuitive effect of narrowing of the conical refraction ring width, disappearance of the dark Poggendorff's ring in the Lloyd's plane, and shift of Raman spots for the low-coherent conical refraction light. We also demonstrate a universal power-law dependence of conical refraction cones coherence degree on the input correlation length and diffraction-free propagation of the low-coherent conical refraction light in the far field.
在本文中，我们运用统一光学相干理论将傍轴圆锥折射模型扩展至部分相干光的情形。对于高斯谢尔模型源，我们展示了圆锥折射相关函数分解为著名的圆锥折射相干模式。假定输入光束电场相位的随机性，我们重新表述并显著简化了严格的圆锥折射理论。这种方法使我们能够以与相干辐射经典情形完全相同的方式来考虑光通过圆锥折射晶体的传播。在此基础上，我们解析推导了焦平面和远场中的圆锥折射强度，这使我们能够解释并严格论证早期的实验结果，以及预测新现象。后者包括圆锥折射环宽度变窄的反直觉效应、劳埃德平面中暗波根多夫环的消失，以及低相干圆锥折射光的拉曼光斑的位移。我们还展示了圆锥折射锥相干度对输入相关长度的普适幂律依赖关系，以及低相干圆锥折射光在远场中的无衍射传播。
